Hi John here. In this video I'm going to take you through how I clean the lichen off
our solar panels. Here's a bit of footage, or photos taken. The first one in September 2019
and you can see there's very little lichen build up. October 2019 surprisingly not much either.
May 2020 again you've just about start to see it. These photos weren't taken specifically to see the
lichen they were just general photos that I took of the array. Here this is April 2021 and you can
just start to see on the bottom edges certainly on the top row over the right hand side of the
old array the little white spots starting to appear and that's basically the lichen.
There's a couple of marks also on the couple of panels that you can see on the left hand array
which is bird poo so you can ignore those. Let's roll on a bit. The next one is from October 2021
and this is with a drone and you can see quite clearly the lichen spots building. If you look
most of them at the bottom edge to start with of the frame and then they creep round
up onto the edge of the face of the panel. And also you can see that they're down the
sides as well down the edges. And I'll explain why that is in a minute. But there's also some
across the whole surface of the panel, small little dots there each one of those dots is
lichen. This is July 2022. Once it's got hold the problem is it just grows exponentially not
fast so like 1 - 2mm a year in some cases but it does build up because each spore, or each
area is expanding and adding new bits to it as well. It doesn't actually take long for it to
build up. You get a lot of lichen. Is it lichen or lichen? lichen, lichen, lichen, lichen, lichen,
lichen. US pronounce it lichen, UK pronounce it lichen. You can amuse yourself with whichever
one you prefer depending on where you are in the world. I'm going to show you what it is.
How does it form. And then and more importantly how to remove it. If you've not seen it up close
this is what it looks. Like it's quite hard and sort of scabby and expands slowly. There's
various types of lichen depending on where you are in the world. Various different colours.
And I found that it's actually a British Lichen Society which is quite interesting and I went
on there to find out exactly what lichen is. And as it clearly says at the bottom here. Lichen is
not a single organism it's a stable symbiotic association between the fungus and the algae.
And that's quite important because what happens is that if you don't clean your solar panels you
get the algae build up and then after that the fungi forms on the algae and starts to
create the lichen. It says here can lichen be removed from growing on solar panels? Well yeah
absolutely. Take away the algae and the lichen does not have a chance to grow. Algae on solar
panels is not given the opportunity to grow if they're cleaned regularly. Bows my head in shame!
Bare in mind mine weren't cleaned regularly! This gives you a close-up on how tough lichen is to
remove. This is on one of our Velux windows and you can see there's a few spots of lichen there
they're just rubbing it with my finger it just doesn't want to move. This is dry, even hard.
However, if you dampen it as I've done here on the solar panel you can see even just with a
finger you can brush off the top part of the lichen to expose the green algae underneath.
It's a lot easier to remove. Now I took that last shot when we had our solar panels repaired back
in February. We had the scaffolding up and while it was up I took the opportunity to a) admire the
view but also to clean our solar panels. Now at the time, I've since got rid of this, but at the
time I had this brush which fits onto the end of a garden hose. And the brush head is quite
firm nylon bristles. And there's also a rubber sort of scraper on the top there which you can
use. I thought perfect! It'll be idea. lt is a bit heavy to use so it was fine from the scaffolding
but I got rid of it because there's no way I was strong enough to use it to clean all our solar
panels from standing on the single story extension we've got, where I can actually reach the solar
panels quite comfortably. It was just too tiring to wield it. It was just too heavy to be able to
successfully clean the panels. I could do about 3 and then you are completely exhausted. Here's
me cleaning the panels, had an on off switch on it. Pumped water up through it and this is just
ordinary tap water straight from the outside tap. You can see it gushing down there. So I'm cleaning
there and you can see that it's not actually removing the lichen. It's cleaning the panels
a bit but even if we turn over the brush and use the scraper... camera work here is difficult to do
with just the one hand... even just with using the scraper you just can't remove the lichen.
It has to be done by hand or chemically that's the only 2 ways you can successfully clean the panels.
As you can see there's still a lot of areas left. This is all damp and again when it's damp you can
get stuck in with your fingers, or a scraper or what have you, and give them a good clean.
This is the second array that went up which I've kept clean since
it's been installed and you can see they're perfect, nice and clean.
This is one of the lichen spots that was nice and damp.
And you can see they all build up along this bottom row here that's because the water
when it rains it sits on that bottom edge channel of the panel and if you don't clean
the panels then you get an algae build up. It also spills over onto the sides of the frame
edges same principle that's why you get a lot of lichen build up along the edge of the frame.
So it's quite easy to clean if you can get to it. And there's the rub! If you've got
scaffolding up you can obviously easily clean them and this is after I clean them
so much much better. The video doesn't really do it justice. Tthe bottom panel
on this second array, these are coming up here, are a lot cleaner because I was able
to get to them all and manually scrape off with my fingernail to get rid of all of the lichen.
But what I learned from this is that just by using a brush you can't get rid of the lichen it
needs something more aggressive than that. You can see here just repeated that previous one,
just a bit closer up. Dry lichen almost impossible to remove, when it's wet it is
a little easier. Again it really needs to be done by hand or with chemicals or both.
So this is on the Velux window again and we had a lichen build up on there too.
It comes off with quite a bit of elbow grease, but it does all come off and remove it.
Now during my research on how to clean solar panels
I learnt that the solar glass, or glass in general, is very pitted. Not a smooth surface
and this is a microscope view of the surface of glass. The algae bonds itself onto all the holes
and valleys and craters in the glass and forms a very strong bond making it difficult to remove it
even by hand. As I mentioned about chemical being one way of doing it. What I got hold of is some
isopropanol alcohol and almost pure 99.9%. And what that does is once you put it on,
put on neat, and that will then kill off the algae and prevent regrowth.
So the only option I had to get to the top array was a ladder, then a roof ladder up onto the
ridge of a roof. And these images here... a bit of video is me sitting on the roof of our house
this is the top row these are the very top edge of the panels. And I went along here with the spray
bottle with the alcohol in it. Spraying as I went and rubbing away the lichen. And that still proved
extremely difficult. Once you've knocked off the surface fungi and left the algae underneath,
because I'm guessing it had been on there so long and baked on so long,
it was extremely difficult to remove. So I ended up buying the window cleaner's glass scraper. And
this proved very effective of scraping up the glass. It does say when you research this that
it is not recommended to use anything abrasive because it can remove the anti-glare coating film
on them. I thought well it's the letter of two evils. If it does start to remove the coating,
you either leave the lichen on there which still keeps growing or you scrape it off there's no
other way of dealing with it. And from the apex I could only reach arms length down the panel so
there were still sort of two-thirds of the panel that I couldn't get to comfortably. Then I bought
an extension pole with an angle joint on it. Combining all those together I was able to then
stand on the extension roof. Spray the panels with water to get the lichen all nice and soft.
And then it was just a case of working along those panels and just scraping off the lichen. It was
actually very straightforward and very easy to do. The view you're looking at there is it's finished.
Once I'd done that I then employed my new soft water system. These are the 2 resin filled
vessels. On the left hand side goes to the garden tap, outside tap. And on the right hand side it
goes to my new water fed pole which is carbon fibre. Proper window cleaner's pole and it has a
brush head specifically for cleaning solar panels. And also that bar across the top is a spray bar as
it's called. Gives you a continuous spray of water over the top so you clean as you bring the brush
down it sprays a cascade of water over the bit you're just cleaned and it sort of washes it all
away. It's actually really really good but the important thing is using the soft water is that
you end up with no water spots ,or water stains. And that was it and that is the panels all nice
and clean and they look superb whereas previously you always saw some little spots of lichen
clinging on for dear life. I've now put in the calendar a monthly cleaning schedule to clean
the panels. Just to preventative maintenance clean now. So there you go any questions drop
them down in the comments below and I'll see you on the next video alright take care bye.